Homogenization involves disaggregating, mixing, re-suspending, or emulsifying the components of a sample using a high-shear process with significant micron-level particle-size reduction of the sample components. Homogenization is commonly used for a number of laboratory applications such as creating emulsions, reducing agglomerate particles to increase reaction area, cell destruction for capture of DNA material (proteins, nucleic acids, and related small molecules), DNA and RNA amplification, and similar activities in which the sample is bodily tissue, bodily fluid, organic plant matter, and/or or another substance. Conventional laboratory equipment for such homogenizing applications includes shaker-mill homogenizing devices. Such shaker-mill homogenizing devices are commercially available for example under the brand name BEADRUPTOR (Omni International, Inc. of Kennesaw, Ga.).
Typical shaker-mill homogenizing devices include a swash plate holding a number of tubes containing the samples and a base unit that generates and transmits a “swashing” motion to the swash plate to homogenize the samples in the tubes using very large sinusoidal forces to vigorously shake the tubes at very high oscillatory rates. The shaking motion of the tubes is a back-and-forth axially reciprocating motion, which can be precisely linear or generally linear with a relatively small curve (the typical swashing action produces a slight arc in the travel path of the tubes in the radial and tangential planes of the swash plate). These high-powered, mechanical-shear, homogenizing devices typically operate at very high speeds of about 0.8 m/s to about 10.0 m/s to process per-tube volumes of about 0.025 mL to about 50 mL. Grinding media, typically a plurality of beads, are included in each tube to increase agitation during processing and thereby reduce the particle size of the sample. As such, these homogenizing devices are commonly referred to as “bead mills.”
After processing, the homogenized sample and the grinding media must be separated. This separation step requires time and/or special equipment that result in increased costs. Additionally, post-separation sample-recovery yields are less than 100 percent due to unrecoverable portions of the sample that are left behind on the grinding media. But without the grinding media, many samples cannot be processed at all given the very-significant forces required to break down the sample particle size.
Accordingly, it can be seen that needs exist for improvements in sample processing with shaker-mill homogenizing devices to address the time and cost problem of post-processing separation of the sample and the grinding media without sacrificing the high homogenizing energies provided by the grinding media. It is to the provision of solutions to these and other problems that the present invention is primarily directed.